WB.15.15

these virtual ports in line with the OpenFlow 1.3 Specification. The controller has to remove these

flow rules or modify them appropriately.

Tunnel Aliveness check using OpenFlow

Detection of Tunnel connectivity status via Openflow message:

If the application does not receive any packet on the tunnel interface for a certain period of time,

it can check if the tunnel path is active by crafting a heartbeat packet and sending an OpenFlow

packet OUT message to the switch with the output port for the heartbeat packet as the tunnel

interface. Once the switch receives the OpenFlow message, it sends the heartbeat frame

encapsulated out the tunnel interface to the application. The application can use this message to

confirm that the tunnel path is working fine.

Figure 3 Tunnel heartbeat via OpenFlow message

OpenFlow and Service Tunnels

The switch notifies the OpenFlow controller about tunnel interface status changes (UP/DOWN) as

well.

Once the controller is notified of the tunnel instance via the OpenFlow switch agent, it can use the

same as a valid output port in its FLOW-MOD messages it pushes to the switch.

If the OpenFlow outport action for a flow rule points to a tunnel virtual port, the packets matching

that flow rule are rerouted to the controller via the tunnel interface.

6 Service Insertion